1. Field of the Invention
This invention has relation to exercise equipment and more specifically to equipment which utilizes fluid resistance type exercising equipment.
2. Description of the Prior Art
Until quite recently, the most commonly used exercise device for muscle development was the barbell which comprised a bar with weights on opposite ends. The weight of the barbell could be varied by adding or removing weights from the ends of the bar. Use of barbells had a number of disadvantages including the time taken to change weights on the barbells to accommodate the capabilities of students in large classes, for example. Barbells are dangerous because of the ever present chance of a student "losing" a weight causing the barbell to fall. Also, muscle development cannot be concentrated in all parts of the body using barbells.
Heretofore, devices which use weights have a fixed weight and, for example, as the lower arm moves from extended position through the position with the elbows close to the body and the lower arm straight out and to a postion with the elbows down and the fists up to the shoulders, the force required to move the weight changes. Therefore, the arm is not equally stressed throughout its range of movement.
It is known to use equipment having activating means such as pivotably movable arms connected to hydraulic or fluid flow resistance cylinders to resist the movement of the user of the equipment in moving such actuating arms. In this regard, the following patents have been issued to Jerry D. Brentham:
U.S. Pat. No. 3,822,599 granted in July of 1974;
U.S. Pat. No. 4,066,259 granted in Jan. of 1978;
U.S. Pat. No. 4,020,627 granted in Dec. of 1980;
U.S. Pat. No. 4,185,818 granted in Jan. 1980;
U.S. Pat. No. 4,247,098 granted in Jan. of 1981;
U.S. Pat. No. 4,254,949 granted in Mar. of 1981;
U.S. Pat. No. 4,258,913 granted in Mar. of 1981;
A company known as "Nautilus" is known to have used elliptical pulleys with weights on the end of activating arms in an attempt to get equal resistance to movement over the entire range of movement.
Universal Athletic Sales of Fresno, Calif. beginning back in the 1954-55 era pioneered the use of weight loaded systems.
No specific search was made on the present invention. However, applicant and those in privity with him are aware of no prior art which is closer than that discussed above and they are aware of no prior art which anticipates the claims herein.